ABSTRACT
OBJECTIVE: The JAK2 46/1 haplotype has recently been described as a major contributing factor to the development of myeloproliferative neoplasm, whether positive or negative forthe JAK2 V617F mutation. The G allele, identified by a single-nucleotide polymorphism known as JAK2 rs10974944, is part of the JAK2 46/1 haplotype. The aim of this study was to verify the association between the presence of the G allele and the development of BCR-ABL-negative chronic myeloproliferative neoplasms in our population. METHODS: Blood and oral mucosa swab samples were obtained from 56 patients of two local Brazilian hospitals who had previously been diagnosed with BCR-ABL-negative chronic myeloproliferative neoplasms. Blood samples from 90 local blood donors were used as controls. The presence of the G allele was assessed using a PCR-RFLP assay after extracting DNA from the samples. RESULTS: The presence of the G allele was strongly associated with the presence of BCR-ABL-negative chronic myeloproliferative neoplasms (p = 0.0001; OR = 2.674; 95% CI = 1.630-4.385) in the studied population. CONCLUSION: In agreement with previous reports, the JAK2 46/1 haplotype, represented in this study by the presence of the G allele, is an important predisposing factor in the oncogenetic development of these neoplasms in our population.
Subject(s)
Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Young Adult , Haplotypes/genetics , /genetics , Myeloproliferative Disorders/genetics , Brazil , Chi-Square Distribution , Chronic Disease , Fusion Proteins, bcr-abl/genetics , Gene Frequency , Mutation/genetics , Polymerase Chain Reaction , Polymorphism, Restriction Fragment Length/genetics , Sex DistributionABSTRACT
The effect of glucagon and isoproterenol (beta-adrenergic agonist) on hepatic glycogenolysis and glycolysis in isolated perfused liver was compared. The levels of isoproterenol and glucagon which promoted the maximal activation of glycogenolysis were 20 muM and 1nM respectively. However, glucagon (1 nM) not only increased glycogenolysis but also inhibited glycolysis. Because adenosine-3'-5'-cyclic monophosphate (cAMP) is a common second messenger to glucagon and isoproterenol, the level of cAMP that simulates the effect of these substances were investigated. The concentration of cAMP that inhibited glycolysis was five times higher (15 muM) than that which stimulated glycogenolysis (3 muM). Similar inhibition of glycolysis was obtained with cAMP agonists resistant to phosphodiesterases, i.e., 8-Br-cAMP and N6-monobutyryl-cAMP (6-MB-cAMP) at the concentration of 3 muM. Thus, apparently glucagon could produce higher cellular levels of cAMP than that obtained with the activation of beta-adrenergic receptors. The higher amount of cAMP could be enough to overcome the action of phosphodiesterases and penetrate in the cytosol creating a favourable gradient to inhibit the enzymes of glycolysis